Jeff Bezos once said that in job interviews he told candidates of 3 ways to work — and that you have to do all 3 at Amazon

Amazon CEO Jeff Bezos has seen his company grow into one of the world's biggest companies.

Back in 1997, Bezos told shareholders that employees at other companies "can work long, hard, or smart, but at Amazon.com, you can't choose two out of three."

Bezos acknowledges his high standards for employees every year, telling shareholders that "it's not easy to work here."

In the 24 years since Amazon was founded, CEO Jeff Bezos has seen his company grow from a modest online bookshop to one of the most valuable companies in the world.

Back in 1997, Bezos was already expecting big things out of his young company. In his annual letter to Amazon shareholders, Bezos described how much effort he expected from his employees.

"When I interview people I tell them, 'You can work long, hard, or smart, but at Amazon.com you can't choose two out of three," Bezos wrote in the 1997 letter.

"Setting the bar high in our approach to hiring has been, and will continue to be, the single most important element of Amazon.com's success."

The New York Times reported in 2015 exactly how bruising the work environment at Amazon could be. Employees were reportedly expected to routinely work late, were encouraged to criticize coworkers' ideas at meetings, and were often found crying at their desks. Amazon disputed many of the claims in the Times investigation, though the newspaper defended its reporting.

Bezos acknowledged his high standards in that 1997 shareholders letter, which he now republishes annually.

"It's not easy to work here," Bezos said. "But we are working to build something important, something that matters to our customers, something that we can all tell our grandchildren about."

He continued: "Such things aren't meant to be easy. We are incredibly fortunate to have this group of dedicated employees whose sacrifices and passion build Amazon.com."